Combined transmitter and receiver.



W. B. THOMPSON. COMBINED TRANSMITTER AND RECEIVER.

APPLICATION FILED JUNE 20, 1911.

Patented Jan. 9, 19 12.

, 3? Thompson.

W; B. THOMPSON. COMBINED TRANSMITTER AND RECEIVER. APPLIOATION FILEDJUNE 20, 1911.

2 8HEETS-SHEET 2.

I Patented Jan. 9, 1912.

To all whom it may concern:

' cover an electrical connection' with the box 12,

at North Conway, in Conway,

'on the line 3-3 of Fig.

rare v "ONE-HALE T0 ARTHUR E.

unison, or NORTH CONWAY, LNEW AMPSHIRE.

. oomfemnn TRANSMITTER am) RECEIVER.

Be it known that I, WILLIAM B. THOMP- SON, a citizen of the UnitedStates, residing in the county of Carroll and State of New Hampshire,have invented certain new and useful Improvements in CombinedTransmitters and Receivers, of which the following is a specification. Iv This invention relates to improvements in telephones and hasparticular reference to combined transmitters and receivers.

The principal object of theinvention is to improve and simplify theconstruction ofdevices of this character. 7

Other objects will develop as the follow ing description proceeds.

In the drawings: Figure 1 is a diagrammatic view of a system in which mydevice is used, Fig. 2 is a vertical section through my device, Fig. 3is a transverse section 2, looking in the direction of the arrows, Fig.4 is a transverse section on the line 4-4 of Fig. 2, looking in thedirection of the arrows, Fig. 5 is a transverse section on the line 5-5of Fig. 2, looking in the direction of the -arrows.

Referring to the drawings, 10 designates a base plate in which issecured the mouth piece 11. To the opposite side of the plate 10 issecured a box 12 having a removable plate 13 in the opposite endthereof,said plate 13 being provided with the insulated bushings 14 for thepassage of the wires. A boss 15 is formed centrally in-the plate 13 andreceives therein the stem 16 of a granular microphone 17,, and is adjustable therein by means of the set screw 18. The upper plate 19 of thegranular micro-- phone has secured thereto a vertically extending rod orstem 20, the upper end of which is secured to'the center of the transg'mitting diaphragm 21. This diaphragingis; located centrally within thebox 12 and close, to the inner end of the mouth piece 11 and issuspended by means of the wires 22 secured at one end to the diaphragm,and at the other end to the box by means of the screws 23. The diaphragm21, the wires 22 and the screws 23- are all metal, and form which isalso of metal. Connected to the i Specification of Letters Patent.Application filed June 20, 1911.

lower end of the stem 20 and extending Patented J an. 9, 1312. SerialNo. 634,361.

through one of the bushings let is a wire 24 leading to the source ofelectrical supply.

Connected to a screw 26, whichis secured in the side of the box 12, isawire 25.

On a ledge 27 is mounted a shelf 28, which has a central opening 29, forthe reception of the stem 20. the electromagnets 30, theends31 and 32 ofthe windingsof which extend through the bushings 14. Directly abovetheelectrdmagnets is a receivingdiaphragm 33, having a centralopening34= for the stem 20.

The wires 24 and 25 of one telephone device are connected to the wires31 and 32 of the other device, so that the movements of the diaphragm 210f one devicewill impart a corres onding movement to'the diaphragm 33 ofthe other device.

If desired, I ma provide each 'of the tele phone devices wit acontrolling switch to cut out the magnets from one telephone, when thattelephone is being used to transmit. Thus the voice will cause the move-Mounted on this shelf arement of the diaphragm 21, and transmit itsmovements to the diaphragm 3230f the other telephone, and preventmovement of the diaphragm 33 of the first telephone when talkmg. Whenusing-the device asa transmit-- ter, the sound waves might cause themovement. of the diaphragm 33, and produce sounds which would render thesounds from the other diaphragm indistinct'or blurred.

Thus when one telephone is talking, the other one is listening, and whenthe other telephonedesires to talk, the receiving magnets are thrownout.

The device is particularly useful in apartment houses, hotels,factories, or on board ships, to displace the ordinary speaking tube,and

provides a much more sensitive, and cpnsequ'ently reliable device thanthe speakfihg' tribe.

,What is claimed is: v

I A combined telephone transmitter and receiver comprising a metallicbox, 'a removable plate on the box, a granular microphone secured tosaid plate within the box, a shelf abote the granular microphone,eIectro magnets on the shelf, a diaphragm arranged above said magnets,said shelf and said diaphragm having central openings, a diaphragm abovethe first mentioned diaphragm, wires secured to the diaphragm and thebox to form electrical connection In testimony whereof I aifix mysignature,

therebetween, a vertical stem extending from in the presence of twoWitnesses.

the ranular micro hone, through the 0 enings of the said Shelf anddiaphragn i, a WILLIAM- BARBER THOMSON 5 mouth-piece arranged on thebox, andmeans Witnesses:

for vertically adjusting the granular micro" MARTHA LEWIS,

phone. VESTA E. TrBBET'rs.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

- Washington, D. G.

